Why is transformer oil containment required in substations and how is it implemented?

Containment prevents environmental release and reduces fire and safety risk if oil leaks or a transformer fails. Implementation typically uses a bunded area or lined pit sized for worst case oil volume, with sloped floors draining to a sump. Oil water separators may be installed for rainwater management. Drain valves are controlled and locked to prevent accidental discharge. Substations also stock spill kits and absorbent booms, and use barriers or separation distances for fire control. The design is aligned with local environmental rules and utility standards.